Field
Embodiments of the present invention generally relate to dimensional control of features formed on substrates, and in particular to plasma process chambers to add or remove microlithography layers from substrates.
Description of the Related Art
In the fabrication of integrated circuits and other electronic devices using a process called microlithography, multiple layers of conducting, semiconducting, and dielectric materials are deposited on or removed from a surface of a wafer substrate, such as a semiconductor substrate or glass substrate. In many cases, as the layers are sequentially deposited on and removed, the substrate is maintained in a carefully controlled environment called a process volume within a process chamber which is thereby protected from the ambient environment. The process chamber includes input and output ports to introduce process gases into the process volume at precise flow rates to react with the substrate. The process chamber may also include energy sources to react with the process gases to facilitate the production of plasma. In this manner, the process chamber may provide temperatures and pressures that facilitate the deposition and removal of these layers while introducing the process gases to chemically react with and/or bond with materials at the surface of the substrate.
In many cases, the precise distribution and control of the process volume is challenging to manage. For example, the flow rates of the process gases at the input and output ports can be difficult to control and performance results between different process chambers may differ due to slight manufacturing differences between process chambers. The unwanted result is sometimes a dimensional non-uniformity error and is measurable after a substrate has been exposed within the process chamber and is later processed. As the demand for higher performance electronic devices are required that have smaller and more precise dimensions, better control of uniformity error is needed to reduce defect rates and improve manufacturing throughput.